Identification of stranded oil after the Hebei Spirit oil spill

Abstract

Even five years after the Hebei Spirit oil spill, highly weathered oil residues were still observed together with newly stranded ambient contaminations and their sources need to be traced not only for scientific reason but also for forensic purpose. Oils from different sources have distinct chemical compositions, which can be used to identify the source of oil pollution. The chemical compositions of spilled oils, however, can be altered in the environment by a number of physicochemical and biological factors, making source characterization ambiguous. In addition, the compositional changes can be variable within a stranded oil residue. Surface of stranded oil is more exposed to various weathering processes such as evaporation, dissolution, photooxidation and microbial degradation, while inner part of oil is remained relatively unchanged. In this study, stranded oil residues collected in the west coast of Korea were analyzed by various analytical methods as source correlation tools, including gas chromatography, mass spectrometry, elemental analysis and stable isotope analysis. The compositional signature of stranded oil was compared with that of possible source oil, especially focusing on the compositional difference between the inner- and outer-parts of oil residues. purpose. Oils from different sources have distinct chemical compositions, which can be used to identify the source of oil pollution. The chemical compositions of spilled oils, however, can be altered in the environment by a number of physicochemical and biological factors, making source characterization ambiguous. In addition, the compositional changes can be variable within a stranded oil residue. Surface of stranded oil is more exposed to various weathering processes such as evaporation, dissolution, photooxidation and microbial degradation, while inner part of oil is remained relatively unchanged. In this study, stranded oil residues collected in the west coast of Korea were analyzed by various analytical methods as source correlation tools, including gas chromatography, mass spectrometry, elemental analysis and stable isotope analysis. The compositional signature of stranded oil was compared with that of possible source oil, especially focusing on the compositional difference between the inner- and outer-parts of oil residues.